A variety of different devices have been developed for absorbing the kinetic energy of impact of colliding automobiles, and for the containment of forces exerted by soil or water. Highway barrier devices, for example, are intended to provide a continuous wall or barrier along the center line of a highway when laid end-to-end to absorb grazing blows from moving vehicles. One commonly used highway barrier is formed of precast reinforced concrete, and is known as the "New Jersey" style barrier. Highway barriers of this type have a relatively wide base including sidewalls which extend vertically upwardly from the pavement a short distance, then angle inwardly and upwardly to a vertically extending top portion connected to the top wall of the barrier. This design is intended to contact and redirect the wheels of a vehicle in a direction toward the lane of traffic in which the vehicle was originally traveling, instead of the lane of opposing traffic. See U.S. Pat. No. 4,059,362.
One problem with highway barriers of the type described above is the high weight of reinforced concrete. A barrier having a typical length of twelve feet weighs about 2,800-3,200 pounds and requires special equipment to load, unload and handle on site. It has been estimated that for some road repairs, up to 40 percent of the total cost is expended on acquiring, delivering and handling concrete barriers. Additionally, concrete barriers have little or no ability to absorb shock upon impact, and have a high friction factor. This increases the damage to vehicles which collide with such barriers, and can lead to serious injuries to passengers of the vehicle.
In an effort to reduce weight, facilitate handling and shipment, and provide improved absorption of impact forces, highway barriers have been designed which are formed of a hollow plastic container filled with water, sand or other ballast material such as disclosed in U.S. Pat. Nos. 4,681,302; 4,773,629; 4,846,306 and 5,123,773. For example, the '302 patent discloses a barrier comprising a container having a hollow interior filled with water, and having fittings for coupling one barrier to another to form a continuous wall. The container structure is formed of a resilient material which is deformable upon impact and capable of resuming its original shape after being struck. Longitudinally extending, spaced traction spoiler channels are said to reduce the area of potential impact and thus the tendency of the vehicle to climb the walls of the barrier and vault over it into the opposing lane of traffic.
The '629, '306 and '773 patents noted above were invented by the present inventor and represent further advances in deformable highway barrier designs. The first two patents disclose barriers which comprise a longitudinally extending container made of semi-rigid plastic which is self-supporting, and has a predetermined shape which is maintained when filled with water, sand or other ballast material. Such devices are connected end-to-end by a key insertable within grooves formed in the end walls of adjacent barriers. Interconnected fill openings are provided which permit adjacent barriers to be filled with water or the like when laid end-to-end.
The '773 patent discloses an improved barrier having sidewalls formed with vertical indentations in order to assist in maintaining the structural integrity of the container, and to create internal baffles for dampening movement of water or other fluid within the container interior. Interlocking male and female coupling elements are formed on opposite end walls of the barrier to facilitate end-to-end connection thereof. Additionally, the base of such barrier is formed with channels to permit the insertion of the tines of a fork lift truck therein for handling of the barrier, and these channels also provide for drainage of water and the like along the ground from one side of the barrier to the other.
Despite the improvements in highway barrier designs noted above, problems nevertheless remain, particularly in controlling the tendency of a vehicle which strikes the barrier to "ride up" or move vertically upwardly along the barrier sidewall toward the opposite lane of traffic. Additionally, the means conventionally employed for interconnecting adjacent, deformable barriers may not be adequate in certain instances, and can result in separation of adjacent barriers particularly upon impact with relatively large and heavy vehicles.